Rotation structure for radiation fans

ABSTRACT

A rotation structure for radiation fans includes a seat to hold a radiation fan and two brackets on the seat to couple with a center hub on a body of the radiation fan. The center hub has two ends to form a first coupling space and a second coupling space to couple respectively with a spindle. Each of the brackets has a bearing corresponding to the spindle. The radiation fan can rotate via the spindles on two ends about a single axis. The spindles do not skew while the radiation fan rotates, thus impact and noise generation can be prevented.

FIELD OF THE INVENTION

The present invention relates to a rotation structure for radiation fansand particularly to a rotation structure to allow a radiation fan torotate about a single axis to reduce abnormal noises.

BACKGROUND OF THE INVENTION

The air fans that generate airflow to disperse heat can be categorizedto many types according to different use environments and utilization.With the fast advance of technologies in information and communicationindustries and the like, the demand of radiation fan for precisionelectronic products grows significantly. The radiation fan adopted foruse on high power and high speed precision electronic devices usually ismade at a smaller size. To overcome the high temperature generated bythe powerful electronic devices, the heat dissipation efficiency of theradiation fan has to be maintained at a desired level within a selectedtemperature range. If the heat energy generated during operation of theproduct cannot be dispelled effectively, the temperature could be toohigh and result in overheat or burn-out of the product. It could causeserious concerns to people's life. Hence most precision electronicproducts have included an air fan to dispel heat.

The conventional radiation fan structure mainly includes a radiation fanwith radial vanes and a seat with a rotation space to hold the radiationfan. The seat has a circuit board and a coil to receive electric powerto drive the radiation fan to rotate. The radiation fan has a spindle inthe center. The seat has a bearing corresponding to the spindle. Thepresent technique is constrained by the available size for installingthe radiation fan. Hence the efficiency of the radiation fan depends onthe rotation speed of the radiation fan. However, at high rotation speedexcessive friction occurs between the spindle and the bearing, and ahigh temperature is generated. As a result, the spindle tends to skewand hit the bearing to generate abnormal noises. To remedy this problem,ceramic bearings that can withstand a greater wearing have beendeveloped. But the ceramic bearings have a greater hardness. Design andfabrication of the anchoring structure are more difficult. And theproblem of high temperature caused by friction also cannot beeffectively prevented.

In short, the present ceramic bearing is difficult to fabricate, andmostly can only be formed in a simpler shape. To produce a morecomplicated shape will increase the cost significantly. It also cannotstore sufficient oil for lubrication. Moreover, replacement is difficultwhen worn out happens. The cost of replacement also is great. All ofthis is the problem of the existing techniques that remains to beovercome.

SUMMARY OF THE INVENTION

The primary object of the present invention is to solve the aforesaiddisadvantages. The present invention provides a seat for holding aradiation fan that has two brackets to couple with a center hub locatedon the radiation fan. The center hub has two ends to form a first and asecond coupling space to hold respectively a spindle. The brackets havebearings corresponding to and coupling with the spindles. Thus theradiation fan has a spindle with two rotation ends and can rotate abouta single axis. The rotation fan can rotate at a high speed withoutskewing or generating noises caused by impact.

Another object of the invention is to lengthen the service life of theradiation fan rotation structure. The first and second coupling spacescommunicate with each other. The center hub has an anchor portionextended to the first and second coupling spaces. The anchor portion canconfine the spindle and also form an oil storing space to holdlubrication oil that leads to the first and second coupling spaces.Hence lubrication between the spindle and the bearing improves andwearing resistance is enhanced.

Yet another object of the invention is to reduce fabrication cost. Thecenter hub and the spindle are coupled together tightly by force so thatthey can rotate together. The center hub is made from a non-ceramicmaterial at a lower material cost. The spindle and bearing are made fromceramics which is wearing-resistant. The center hub is made of metal andis easier to fabricate. It can withstand wearing better than othermaterial and the material also can be procured easier.

The foregoing, as well as additional objects, features and advantages ofthe invention will be more readily apparent from the following detaileddescription, which proceeds with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of the radiation fan structure of the presentinvention.

FIG. 2 is an exploded view of the rotation structure of the radiationfan of the present invention.

FIG. 3 is a sectional view of the radiation fan of the presentinvention.

FIG. 4 is a top view of the radiation fan of the present invention.

FIG. 5 is a schematic view of an embodiment of the rotation structure ofthe present invention.

FIG. 6 is a schematic view of another embodiment of the rotationstructure of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please referring to FIGS. 1 and 2, the present invention aims to providea rotation structure for a radiation fan 1. The radiation fan 1 includesa body 10 and a plurality of radial vanes 11 extended from the body 10.The body 10 has a through hole 12 to hold a center hub 13 in a tightlymanner. The center hub 13 has two ends forming respectively a firstcoupling space 130 and a second coupling space 131 to hold a spindle 40in a tightly manner. The radiation fan 1 is held in a seat 3 whichincludes a holding member 30 and a lid 31. The seat 3 has a rotationspace inside to enable the radiation fan 1 to rotate therein. Therotation space also contains a driving mechanism to rotate the radiationfan 1 (as shown in the drawings, the driving mechanism may include acoil 20 and a circuit board 21 to receive electric power and transformto magnetic force to drive the radiation fan 1. As the technique relatedto the driving mechanism is known in the art and not a feature of theinvention, details are omitted.) The seat 3 has two brackets 32corresponding to the two ends of the hub 13. Each of the brackets 32 hasa bearing 50 corresponding to and coupling with the spindle 40 to allowthe two ends of the hub 13 to rotate about a single axis.

Referring to FIG. 2, the center hub 13 has respectively an anchorportion 133 on the first and second coupling spaces 130 and 131. Theanchor portions 133 separate the first and second coupling spaces 130and 131 and form an oil storing space 132 between them. The first andsecond coupling spaces 130 and 131 have respectively an opening on oneend to hold the spindle 40. The spindle 40 has a detent portion 41 onone end to be confined in the first and second coupling spaces 130 and131 and anchored by the anchor portion 133. The spindle 40 has anotherend forming a contact portion 42 to be pressed and coupled by thebearing 50. Hence the spindle 40 can be held and confined securely bythe bracket 32 and each of the two ends of the center hub 13.

In the embodiment set forth above, the first and second coupling spaces130 and 131 may communicate with each other to form the oil storingspace 132 to reduce wearing between the spindle 40 and the bearing 50during rotation so that the life span of the rotation structure canincrease. Moreover, the hollow hub 13 consumes less material and canreduce the weight of the radiation fan and also reduce energyconsumption during rotation.

Refer to FIGS. 3 and 4, the center hub 13 of the radiation fan 1 has thetwo ends to hold respectively and tightly the spindle 40 which isanchored by the anchor portion 134. Then the center hub 13 is held bythe bearings 50 of brackets 32. Hence the radiation fan 1 can rotateabout a single axis without moving away from the bearings 50. Thereforethe hub 13 does not skew and abnormal noises generated by impact can beprevented. In addition, the contact portion 42 has an outer diametersmaller than the outer diameter of the center hub 13, and the bearing 50has a rotation trough 51 larger than the outer diameter of the contactportion 42. The contact portion 42 is formed from the spindle 40 in atapered manner. The profiles of the contact portion 42 and the rotationtrough 51 are shown in FIG. 3. The contact portion 42 has an apex formedin a conical shape with an arched end or a cylindrical strut with anouter diameter smaller than the center hub 13. Moreover, the contactportion 42 and the rotation trough 51 of the bearing 50 may be switched.As previously discussed, the spindles 40 have respectively a detentportion 41 confined by the first and second coupling portions 130 and131, and are coupled by the bearing 50 so that the spindles 40 canrotate in the first and second coupling portions 130 and 131. Hence thecenter hub 13 can be positioned on the central axis of the spindle 40.Due to the spindles 40 and the center hub 13 are fabricated separately,assembly of the spindles 40 and the center hub 13 is easier. Such astructure also facilitates replacement of the center hub 13 if damageoccurs.

The spindle 40 may be made from ceramics to enhance wearing resistance.As the ceramics is porous, it can store lubrication oil and increase theservice life. The center hub 13 is made from a non-ceramic material toreduce material cost. It usually is made of metal and is easier tofabricate to form the anchor portion 133. Thus fabrication of the centerhub 13 is easier and the production cost is lower.

Refer to FIGS. 5 and 6 for two different embodiments of the rotationstructure of the invention. The main feature is: when the radiation fan1 rotates, the through hole 12 and the center hub 13 a form rotationalcontact points or surfaces between them. Through these contact points orsurfaces the body 10 is driven to rotate. The through hole 12 and thecenter hub 13 a form the contact points or surfaces through same ordifferent shapes so that the center hub 13 a can be driven by the body10 to rotate. Referring to FIG. 5, the through hole 12 is circular, andthe center hub 13 a is a triangle held in the through hole 12 so thatthe through hole 12 and the center hub 13 a form three rotationalcontact points. Referring to FIG. 6, the through hole 12 a is a triangleand the center hub 13 b also is a triangle. Hence the through hole 12 aand the center hub 13 b form rotational contact surfaces. Through therotational contact points or surfaces, when the radiation fan 1 rotates,the body 10 drives the center hub 13 to rotate. Hence when the radiationfan 1 rotates at a high speed, the friction force between the body 10and the center hub 13 is not great enough to generate a floatingphenomenon.

While the preferred embodiments of the invention have been set forth forthe purpose of disclosure, modifications of the disclosed embodiments ofthe invention as well as other embodiments thereof may occur to thoseskilled in the art. Accordingly, the appended claims are intended tocover all embodiments which do not depart from the spirit and scope ofthe invention.

1. A rotation structure for radiation fans, comprising: a radiation fanincluding a body and vanes extended from the body, the body having acenter hub; and a seat having a rotation space to hold the radiation fanand two brackets on two sides corresponding to two ends of the centerhub; wherein the two ends of the center hub have respectively a firstcoupling space and a second coupling space to hold a spindle, each ofthe brackets having a bearing corresponding to the spindle so that theradiation fan rotates via the two spindles about a single axis.
 2. Therotation structure for radiation fans of claim 1, wherein the spindle isheld tightly on each of the two ends of the center hub.
 3. The rotationstructure for radiation fans of claim 1, wherein the center hub hasrespectively an anchor portion in the first coupling space and thesecond coupling space, the spindle being confined by the anchor portionand the bearing.
 4. The rotation structure for radiation fans of claim3, wherein the anchor portion defines an oil storing space in the centerhub to store lubrication oil, the oil storing space communicating withthe first coupling space and the second coupling space.
 5. The rotationstructure for radiation fans of claim 1, wherein the spindle has aconfining rotational surface corresponding to the shape of the bearing.6. The rotation structure for radiation fans of claim 1, wherein thebody has a through hole to hold the center hub, the through hole and thecenter hub forming a tight coupling.
 7. The rotation structure forradiation fans of claim 6, wherein the through hole and the center hubare formed in mating shapes.
 8. The rotation structure for radiationfans of claim 6, wherein the through hole and the center hub are formedin different shapes.
 9. The rotation structure for radiation fans ofclaim 1, wherein the center hub is integrally formed on the body.